1. Field of the Invention
This invention relates generally to fluid flow valving devices. More specifically, the present invention relates to a valve usable with a suction catheter. Even more specifically, the present invention relates to a suction control valve useable with suction catheters attachable to a respirator manifold of a respiratory system.
2. Prior Art
Respiratory systems for ventilation of critically ill patients are now commonly used in medical facilities. The purpose of the respiratory system is to assist the patient in maintaining adequate blood oxygenation levels without overtaxing the patient's heart and lungs. Typically, a prior art respiratory system includes a tracheal tube positioned either directly or through the nose or mouth into the trachea of a patient. The tracheal tube is connected to a manifold at one port position thereof, and a source of breathable gas is connected at a second port thereof.
While a patient is attached to a respiratory system, it is periodically necessary to remove fluid from the patient's trachea or lungs. In the past this procedure necessitated disconnections of the respirator system, either by removing the manifold or by opening a port thereof, and inserting a small diameter suction catheter down the tracheal tube and into the patient's trachea and lungs. The fluid was then suctioned from the patient and the suction catheter was removed and the respirator system reassembled. Because of the necessary interruption in respiratory support to perform this procedure, a patient's blood oxygen often dropped to an unacceptably low level during suctioning, even when other previously known breathing assistance efforts were simultaneously provided.
A known solution to the above problem has been to place an additional port on the respirator manifold which is adapted to receive a connector of a suction catheter device. A suction catheter device such as used with this type of respirator manifold is adapted to allow the suction catheter to remain positioned within the respirator manifold without the necessity of attachment or detachment thereof between uses, thereby avoiding substantial manifold pressure loss. The suction catheter device includes a sleeve which envelopes the suction catheter in order to prevent contamination of the suction catheter surface which must be repeatedly inserted into and removed from the patient's trachea and lungs. This type of suction catheter device allows continuous respiratory support of the patient during suctioning of fluid from the patient's trachea and lungs, and is commonly controlled by means of a valve located in fluid flow connection between the catheter and the suction source therefore. A valve of this type which is generally exemplary of the prior art is shown in U.S. Pat. No. 4,872,579 issued to Palmer. The Palmer valve selectively communicates vacuum pressure into the interior of a catheter tube when it is desired to evacuate respiratory fluids. It is normally biased to a closed position to prevent vacuum flow until the operator thereof initiates a manual displacement of a valve actuator to open the catheter tube to the vacuum source. The valve actuator is also designed to be rotatable relative to the remainder of the valve from a closed position to a locked position which prevents actuation of the valve actuator between uses.
Other suction catheter devices of this type include U.S. Pat. No. 5,335,655, U.S. Pat. No. 5,337,780, and U.S. Pat. No. 5,377,672 issued to Kee, the inventor of the present invention and commonly assigned herewith.
The above and other prior art valving devices however suffer from several drawbacks, including but not limited to, being manufactured of relatively numerous and expensive components which are difficult and expensive to assemble, and being made to a design which does not allow for complete gas sterilization of the device after its assembly due to inaccessible and trapped regions therein which cannot be reliably penetrated by the sterilization gas.